Fluid pressure operated variable pitch propeller



1m30, 1940. RJ. RUTHSETAL 188,313

FLUID PRESSURE OPERATED vAR'IABLE FITCH PROPELLER Filed Aug, l, 1988 l NVENTORS l @aerJ .ew/s BY #Heey L ...Doos o/Y A( ATTORNEY Patented Jen. so. 1940 FLUID PRESSURE OPERATED VARIABLE FITCH PBOIEILER Robert J. Bilthl, Baltimore, Md., and Ihr!! L.

, Dodson, United State! NIV! Application August 10, 1938, Serial No. 224,067

1Ciaim.

(CL 17d-163) '(Granted underthe actief Maren 3, 1888, al amended April 30, 192B; 870 0. G, '151) This invention relates to variable pitch PrO- pellers and it has for its principal object the provision of a new and improved propeller of the character described in which the pitch of the several blades may -be adjusted by hydraulic pressure operated means acting through the propeller shaft and hub while the same are in motion.

With these and other objects in view, as well as other advantages that may be incident to the use of the improvements, the invention consists in the parts and combinations thereof hereinafter set forth and claimed, with the understanding that the several necessaryelements constituting the same may be varied in proportion and arrangement without departing from the nature and scope of the invention. as defined in the appended claim.

In order to make the invention more clearly understood, there are shown in the accompanying drawing means for carrying the invention into practical use, without limiting the improvements in their useful application to the particular construction which, for the purpose of explanation.

have been'made the'subject of illustration.

In the accompanying drawing:

The single ligure in the accompanying drawing is a diagrammatic view partly in side elevation and partly in longitudinal section of a propeller constructed in accordance with the invention.

Referring to the drawing. a variable pitch propeller embodying the invention is shown as comprising a hub Il secured to a drive shaft II and r having a plurality of circumierentially arranged sockets I2 formed therein, in each of which the root portion I3 of a blade Il is mounted for rotation about a radial axis.

The hub is also formed with a chamber I5 of triangular cross-section in which a block il of similar shape is mounted for fore and aft sliding movement. Each face of the block I6 is formed with a transverse slot i1 in which a block I8 is slidably mounted and is engageable by an `eccentrically disposed crank pin I9 xed to the root I3 of the blade Il. The block I6 is reciprocated in order to swing the blades I4 about their axes of rotation by means of a rod which is fixed to a piston 2i mounted in-a cylinder 22 formed in the forward end of the hub. Fluid under pressure is supplied to the 'cylinder 22 in order to reciprocate the piston, .through passageways 23 and 2l extending longitudinally through the hub I0 and shaft II whichv communicate with chambers 2E and 26, rpectively, formed by cup-shaped mem- 55 bers 21 .on each side oi a collar 28 provided on the shaft II. Leakage between the chambers 28 and 26 and past the collar 2l is prevented by packing 29 and from these chambers around the shaft by glands 30. Fluid under pressure is at times sup- 5 In operation, ,when it is desired to alter the 10 pitch of the blades Il in one direction, iiuid is forced into the right-hand end of the cylinder 22 through the pipe 3|, chamber 2l and passageway 23, the fluid in the left-hand end ofthe cylinder escaping through the passageway 2l, chamber 26 15 and pipe 32. If it is desired to alter the pitch oi' the blades in an opposite direction the iiow of iluid under pressure is reversed.4

The propeller blades Il are of the balanced type, that is to say, the area of thrust on opposite 2o sides of the radial axis about which they are adjustable, is equal so that the power required to turn the blade will be the same in either direction.

It will be understood that the above description 25 and accompanying drawing comprehend only the general and preferred embodiment of the invention and that various changes in construction, proportion and arrangement of the parts may be made within the scope of the appended claim 30 without sacrincing any of the advantages of the invention.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment ci any royalties thereon or therefor.

We claim:

A variable pitch propeller comprising a shaft having a collar thereon and iiuid pressure inlet o and outlet passageway: therein, a hub fixed t0 said shaft and having a iiuid pressure cylinder formed therein communicating with said passageways, a piston in said cylinder. a blade mounted on said hub for rotation about aradially extending axis, means operatively connecting said piston with said blade whereby reciprocation of the former will rotate the latter about said axis, and a pair oi' cup-shaped members clamped together against `opposite sides of said collar and forming o therewith inlet and outlet chambers communieating with the passageways in said shaft and adapted to selectively supply duid under pressure to said cylinder on opposite sides of said piston.

ROBERT J. RUTHS. maar L. noneoN. u 

